1. Field of the Invention
The present invention relates to the field of controlling the monitoring of a processor that operates in different domains and in particular, in certain preferred embodiments, to the control of the debugging and tracing functions of such processors.
2. Description of the Prior Art
In order to be able to monitor processors to find any faults that may be present debug and trace applications have been developed. In order for these applications to be able to function properly, these applications have conventionally had access to the entire processor. This is generally needed as it allows the monitoring functions to locate a fault that may be anywhere on the processing system.
With processors that operate in more than one domain, for example, processors that operate in a secure domain and a non-secure domain, allowing a monitoring application access to the entire processor enables it to find a fault located anywhere on the system. However, such a comprehensive monitoring function may also allow data movement or leakage between the two domains. In the case of a secure and a non-secure domain this could potentially provide access to information that should be secure and could therefore introduce a weakness into the security of such a system. However, not allowing debug or trace to access certain parts of a system, makes it difficult, if not impossible, to locate certain faults that may occur in a non-accessible part of the system.
Accordingly, it is desirable to provide an improved way of controlling monitoring functions to enable a processor to be monitored while reducing the risk of data leakage between domains.